The present invention broadly relates to fluid mixing devices, especially hot and cold water mixing devices and, more specifically, pertains to a new and improved construction of an electrically controlled mixing fixture for fluids, especially hot and cold water, typically a plumbing fixture, also referred to in the art as a plumbing fitting.
Generally speaking, the electrically controlled mixing fixture for hot and cold fluids, especially hot and cold water, is of the type comprising an inflow or infeed element provided with inflow or inlet openings and an annular or gap-shaped flow channel for the fluids. There is also provided a temperature measuring element or means arranged at the region of the annular or gap-shaped flow channel.
In the German Petty Pat. No. G. 8520484.6, published Oct. 3, 1985, there is disclosed a measuring head for measuring the temperature of fluent or flowable fluids. In that arrangement, the fluids are conducted through two inflow openings in tangential direction into a ring-shaped flow channel. This ring-shaped flow channel is bounded in radial direction internally by a hollow cylinder of increased thermal conductivity and at the outside by a housing formed of a plastics material. At the end located remote from the two inflow openings the ring-shaped flow channel is connected by radial recesses with a bore provided in the hollow cylinder. This bore, in turn, flow communicates with an outflow or outlet opening. In order to swirl or place into turbulent motion the infed fluids and to ensure for a good heat transfer to the hollow cylinder impact plates are provided at the hollow cylinder which extend in the circumferential direction thereof and protrude into the ring-shaped flow channel. At the thick-wall hollow cylinder there are provided axial bore for receiving thermoelements which measure the temperature of the hollow cylinder. In the ring-shaped flow channel both of the fluids are thus agitated or swirled and admixed and due to fluid circulation around and within the hollow cylinder the latter reaches a temperature which approximately corresponds to the temperature of the admixed water which outflows through the outflow or outlet opening. With this heretofore known construction of measuring head it is not thought to be possible to achieve a very rapid and exact determination of the temperature of the mixed water owing to the sluggish or inertia-prone heating up of the hollow cylinder and the locally prevailing temperature differences.